a)x+3y-3z=(x+2y)+(y-3z)=17+4=21
b)(3x+6y)+(2y-6z)=3(x+2y)+2(y-3z)=3x17+2x4=51+8=59
c)2x+5y-3z=2(x+2y)+(y-3z)=2x17+4=38
d)(2x+4y)*(x+4y-6z)=2(x+2y)*[(x+2y)+2(y-3z)]=2x17x(17+8)=34x25=850
Sper ca te-am ajutat xD
